The present invention relates to a connector terminal, particularly to a connector terminal having a contact portion that comes into contact with a counter connector terminal and a hold portion that is held in a connector housing.
The invention also relates to an electric connector using a connector terminal.
In connectors where large current flows, such as a connector for a power supply, the configuration has heretofore widely been employed in which electric connection is established by inserting a plug terminal in a flat plate shape into a socket terminal in a box shape such that the plug terminal is sandwiched from top and bottom between a plurality of contact points of the socket terminal.
For instance, JP 2010-61962 A discloses a socket terminal 4 of a bus bar 3 to be connected to a flat plate shaped plug terminal 2 of a secondary cell 1 as shown in FIG. 19. The plug terminal 2 of the secondary cell 1 is held in a secondary cell-side housing 5 attached to the secondary cell 1 and projects in a recess 5A of the secondary cell-side housing 5. The socket terminal 4 of the bus bar 3 is held in a bus bar-side housing 6 and has two contact points 7 and 8 that project in a recess 6A of the bus bar-side housing 6 and face each other. Of the two contact points 7 and 8 of the socket terminal 4, one contact point 7 forms a spring contact point that is elastically displaceable in a direction toward the other contact point 8 in the recess 6A of the bus bar-side housing 6.
As shown in FIG. 20, upon insertion of the bus bar-side housing 6 of the bus bar 3 into the recess 5A of the secondary cell-side housing 5, the plug terminal 2 of the secondary cell 1 is inserted into the recess 6A of the bus bar-side housing 6 and sandwiched by the two contact points 7 and 8 of the socket terminal 4 from opposite sides. At this time, contact pressure occurs between the plug terminal 2 of the secondary cell 1 and the socket terminal 4 of the bus bar 3 owing to the contact point 7 of the socket terminal 4 that forms the spring contact point, and the plug terminal 2 of the secondary cell 1 and the socket terminal 4 of the bus bar 3 are fitted with each other to establish an electrically continuous state.
The use of the thus-configured bus bar 3 enables a plurality of secondary cells 1 to be electrically connected with each other.
Meanwhile, when vibration or the like is applied to the secondary cell 1 and the bus bar 3 in the state where the plug terminal 2 of the secondary cell 1 and the socket terminal 4 of the bus bar 3 are fitted with each other and the contact points 7 and 8 of the socket terminal 4 are in contact with the plug terminal 2 as shown in FIG. 20, contact parts of the socket terminal 4 and the plug terminal 2 may be moved relative to each other, resulting in poor contact. This occurs because, when the contact parts of the socket terminal 4 and the plug terminal 2 are moved and rubbed against each other, platings of the contact parts are peeled off, leading to corrosion of the contact parts and increase in contact resistance.
To cope with it, one possible measure is to, in the socket terminal 4 of the bus bar 3 shown in FIG. 19, provide a spring portion between a contact portion having the contact points 7 and 8 that come into contact with the plug terminal 2 of the secondary cell 1 and a hold portion held in the bus bar-side housing 6 such that the contact portion and the hold portion are coupled by the spring portion to be elastically displaceable. With this configuration, even when vibration or the like is applied, the spring portion deforms to thereby prevent relative movement of the contact parts. As a result, poor contact is less likely to occur.
However, while it is preferable that the spring portion with a longer spring length be provided between the contact portion and the hold portion in order to prevent poor contact from occurring, such a longer spring length causes increase in the distance from the contact portion to the hold portion, resulting in a larger connector.